At present, stackable trays are used for delivering to and displaying in stores bread loaves. These trays are formed of a body of rigid plastics material and consist of a bottom wall integrally formed with opposite side walls, a rear wall and a front wall, the latter providing an access area to the bread loaves. The structural configuration of the trays is such that, for a stacked arrangement, they are simply placed one on top of the other, the lower edge of the opposite side walls of a tray resting on the upper edge of the opposite side walls of the lower tray.
It has been found that, when the trays are loaded and a number of them are stacked, there is a downward sagging force exerted on the bottom wall, especially adjacent the access area of the front wall, thus causing an inward movement of the side walls, which movement is further increased as the number of loaded superposed trays becomes important. One solution used is to increase the thickness of the structure of the front wall while another is to include a metallic reinforcement in the front wall of the tray.
A first method of overcoming the above problems has been described in applicant's co-pending U.S application Ser. No. 08/230,375 filed Apr. 20, 1994. Its disclosure describes a stackable tray which is formed of a body of rigid plastic material with a bottom wall integrally formed with opposite side walls and front and rear walls; each side wall is provided with an upper edge flange which is engageable in a recessed area defined in the lower edge of a superposed similarly constructed tray. The location of the recessed area with respect to the upper edge flange is such as to force outwardly the side walls during stacking engagement, thus causing internal stresses in the bottom wall which counteract the sagging which occurs when loads are supported on the bottom wall.